Fungicides

Retired UT Extension Agent talks about fungicides, how they work and demonstrates how to apply them. Common fungal diseases include rots on fruit, blights on tomatoes, and leaf spots on ornamental plants. Most fungal diseases on plants are spread by wind moving spores from one plant to another. Fungicides are applied to leaves of a plant preventatively. Then a spore lands on the protected leaf the fungicide kills the spore. Once the fungus is established on a leaf it can’t be cured with fungicide. Rain or irrigation can easily wash the fungicide off. This requires re-treatment to maintain the protection. Fungicides should be applied to both the top and bottom of the leaves. Try to apply the fungicide before you have the problem. You should try to get good coverage on the plant.